Friday, 4/4/14 Day 2 2- Fill out your Agenda. Science Starter: Science Starters Sheet Agenda 2- Fill out your Agenda. Science Starter: AIMS Review Questions 4- When you are done, read your AR book.

Please put these in the Friday box. Newton(Sir Isaac)-was an English physicist and mathematician who is widely recognized as one of the most influential scientists of all time. formulated the laws of motion. Preistly(Joseph)-(1733–1804), best remembered for his discovery of the gas that would later be named "oxygen," Baker 2003/2004

Whose got Genes? Genes, Heredity, & DNA www.sciencequeen.net Baker 2003/2004

What is GENETICS? The study of how traits are inherited through the interactions of genes. Baker 2003/2004

What are genes? Genes are a segment of DNA on a chromosome that controls a particular trait. Genes are located on the chromosomes in the nuclei. Each organims has a fixed number of chromosomes. Humans have 23 pairs (46) chromosomes. Genetics is the study of how traits are passed on from one generation to another                                    Baker 2003/2004

Define TRAIT Ways of looking, thinking, or being Traits that are genetic are passed down through the genes from parents to offspring Baker 2003/2004

Describe RECESSIVE A trait that is covered over, or dominated, by another form of that trait and seems to disappear Hidden when the other copy of the gene contains the dominant allele. A recessive allele shows up only when there is no dominant allele present Shown with a lower-case letter Baker 2003/2004

Describe DOMINANT A trait that covers over, or dominates, another form of that trait Trait that always shows up, even when only one of the two alleles is in the dominant form Shown by a capital letter Baker 2003/2004

Define GENOTYPE An organism's genetic makeup Baker 2003/2004

Outward physical appearance and behavior of an organism Define PHENOTYPE Outward physical appearance and behavior of an organism Baker 2003/2004

What is a PUNNETT SQUARE? Used to determine the likely hood that the offspring receives a certain trait. An uppercase letter stands for a dominant allele Lowercase letters stand for recessive alleles Baker 2003/2004

Punnett Squares Sample Problem 1.   In roses, red flowers are dominant over white flowers. What are the possible offspring when a homozygous red rose is crossed with a homozygous white rose. Baker 2003/2004

Generation 1 (I Do) R R Red rose = RR white rose = rr R r R r r Genotype 4 Rr Phenotype 100% Red Rose R r r R r Baker 2003/2004

Generation 2 (We do) R r r r R r r Red rose = Rr white rose = rr R r r Genotype 2 Rr 2 rr Phenotype 50% Red 50% White R r r r r Baker 2003/2004

Generation 3 (You do) R r Red rose = Rr R r R R R Genotype Phenotype 75% Red 25% White R r r r r Baker 2003/2004

Whose got Genes? Part 2 Genes, Heredity, & DNA Baker 2003/2004

The passing of traits from parent to offspring Define HEREDITY The passing of traits from parent to offspring Baker 2003/2004

Define ALLELE The different forms of a trait that a gene may have One form of a gene Baker 2003/2004

What is HOMOZYGOUS? Both alleles [forms of the gene] are the same When offspring inherit two dominant genes, (one dominant gene from each parent) they are said to be homozygous dominant When offspring inherit two recessive genes, (one recessive gene from each parent) they are said to be homozygous recessive AA aa Baker 2003/2004

What is HETEROZYGOUS? When alleles occur in different forms Aa What is HETEROZYGOUS? When alleles occur in different forms When offspring inherit one dominant gene and one recessive gene, they are said to be heterozygous Since the dominant gene will be expressed, they are said to be heterozygous dominant Baker 2003/2004

Generation 1 B Brown Eyes are Dominant to b Blue Eyes B b Heterozygous Homozygous recessive b b B b b Genotype 2 Bb 2bb Phenotype 50% Brown 50% Blue B b b b b Baker 2003/2004

Generation 2 B Brown Eyes are Dominant to b Blue Eyes B B Homozygous Dominant Homozygous Recessive B b B b b Genotype 4 Bb Phenotype 100% Brown Eyes b B b B b Baker 2003/2004

Generation 3 B Brown Eyes are Dominant to b Blue Eyes B B Homozygous Dominant Heterozygous B B B B B Genotype 2 BB 2 Bb Phenotype 100% Brown Eyes B b b B b Baker 2003/2004

Three reasons why cells reproduce by asexual reproduction: 1. Growth 2 Three reasons why cells reproduce by asexual reproduction: 1. Growth 2. Repair 3. Replacement Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. Cell that reproduce by asexual reproduction reproduce constantly.

Animated Mitosis Cycle http://www.cellsalive.com/mitosis.htm Interphase Prophase Metaphase Anaphase Telophase & Cytokinesis

Interphase occurs before mitosis begins Chromosomes are copied (# doubles) Chromosomes appear as threadlike coils (chromatin) at the start, but each chromosome and its copy(sister chromosome) change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm

Prophase 1st step in Mitosis Mitosis begins (cell begins to divide) Centrioles (or poles) appear and begin to move to opposite end of the cell. Spindle fibers form between the poles. Centrioles Sister chromatids Spindle fibers

Metaphase 2nd step in Mitosis Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers

Anaphase 3rd step in Mitosis Chromatids (or pairs of chromosomes). separate and begin to move to opposite ends of the cell Centrioles Spindle fibers

Telophase 4th step in Mitosis Two new nuclei form. Chromosomes appear as chromatin (threads rather than rods). Mitosis ends. Nuclei Nuclei Chromatin

Cytokinesis occurs after mitosis Cell membrane moves inward to create two daughter cells with identical chromosomes.

Animal Mitosis -- Review Interphase                                                              Prophase                                                              Metaphase                                                              Anaphase                                                              Telophase                                                             

Plant Mitosis -- Review Interphase                                                              Prophase                                                              Metaphase                                                              Anaphase                                                              Telophase                                                             

Meiosis is the type of: Cell division by which eggs and sperm are produced. One parent cell produces four daughter cells. Daughter cells have half the number of chromosomes found in the original parent cell

During meiosis, DNA replicates once, but the nucleus divides twice.

First division of meiosis Meiosis I First division of meiosis

First Division of Meiosis Same as the mitosis. Cell divides into 2 cells with the same genetic information

Second Division of Meiosis

Second Division of Meiosis Prophase 2: DNA does not replicate. Metaphase 2: Chromosomes line up at the center of the cell Anaphase 2: Centromeres divide and sister chromatids move separately to each pole. Telophase 2: Cell division is complete. Four haploid daughter cells are formed.

Meiosis http://www.biosci.uga.edu/almanac/bio_103/notes/apr_3.html.

Meiosis Animation http://www.rothamsted.bbsrc.ac.uk/notebook/courses/guide/movie/meiosis.htm

Differences in Mitosis & Meiosis Asexual Cell divides once Two daughter cells Genetic information is identical Creates regular cells Meiosis Sexual Cell divides twice Four haploid daughter cells Genetic information is different Only creates sex cells E.g. sperm and eggs

Literal definition: the act of living together What is symbiosis? Literal definition: the act of living together What it means: Two organisms that live together Temporarily or for a longer time At least one of the organisms benefits from the relationship

What are the different kinds of symbiosis? Mutualism Commensalism Parasitism one organism benefits both organisms benefit one organism benefits one organism is unaffected one organism is harmed

Parasitism: one benefits, one is harmed Example 1: Acacia plant with ant galls Ants lay eggs on acacia tree Acacia covers the infected area with brown flesh (gall) Parasitism: one benefits, one is harmed

Mutualism: both benefit Example 2: Moray Eel with Cleaner Fish Moray Eel gets a clean mouth Cleaner Fish gets a meal Mutualism: both benefit

Commensalism: one benefits, one is unaffected Example 3: Cattle with cattle egrets Cattle stir up insects as they eat grass Egrets hang around and eat insects Commensalism: one benefits, one is unaffected

Mutualism: Both benefit Example 4: Clown fish with anemone Clown fish gets protection Anemone gets food Mutualism: Both benefit

Mutualism: both benefit Example 5: Antelope with Oxbird Antelope gets rid of parasites Oxbird gets a meal Mutualism: both benefit

Parasitism: one benefits, one is harmed Example 6: Taenia worm in human eye Worm infects human blood stream Human may go blind Parasitism: one benefits, one is harmed